1. Field of the Invention
The present invention relates to a coating apparatus for scratches of a glass bottle of beer or soft drinks such as aerated drink, cola and similar drinks, which scratches appear on the barrel surface of the glass bottle.
2. Description of the Prior Art
The glass bottles rub mainly together in their bottling and transporting operations to produce the scratches on their barrel surface, which scratches appear, for example, usually as a whity band in the barrel surface of the beer bottle and the like. Under the existing circumstances, as the number of times of recovery and re-use of the glass bottle increases, the glass bottle deteriorates in its appearance due to such barrel scratches so that the bottled drink deteriorates its product value. As a means for preventing such deterioration of the product value, there has been developed a conventional coating apparatus for the scratches of the bottle in which apparatus a coating liquid is applied onto the scratched barrel surface of the bottle by means of a coating roller. As shown in FIG. 1, the conventional coating apparatus comprises: a transfer unit 152 constructed of a rotary disc on which the bottle 151 is placed and transferred in rotatable manner; a coating roller 153 which is eccentrically provided relative to the rotary disc so that a peripheral surface of the coating roller 153 is brought into contact with the barrel surface of the transferred bottle 151 in slidable manner to apply the coating liquid of the barrel surface of the bottle 151; an intermediate roller 154 and a feed roller 155 for uniforming in thickness the coating liquid into a thin film which is applied to the peripheral surface of the coating roller 153; and a spray gun for spraying the coating liquid to feed the same to the feed roller 155; wherein the barrel surface of the bottle 151 is brought into contact with the peripheral surface of the rotating coating roller 153 in slidable manner to apply the coating liquid from the coating roller 153 to the barrel surface of the bottle 151 when the bottle 151 is transferred to area "C" by means of the transfer unit 152.
However, in the above conventional apparatus, since each of the rollers 153, 154, 155 rotates at its fixed rotational speed, an amount of the coating liquid fed in the form of the thin film to the coating roller 153 from the feed roller 155 through the intermediate roller 154 remains always constant even when an amount of the coating liquid fed through the spray gun 156 is varied. Consequently, it is impossible to vary an amount of the coating liquid applied to the barrel surface of the bottle 151 from the coating roller 153. As a result, in case that many scratches exist in the barrel surface of the bottle 151, it is impossible to increase an amount of the coating liquid applied to the barrel surface of the bottle 151, or in contrast with this, in case that few scratches exist in the barrel surface of the bottle 151, it is impossible to decrease the amount of the coating liquid applied to the barrel surface of the bottle 151, whereby an application efficiency of the coating liquid is very poor. This is one of the defects inherent in the conventional apparatus. Further, in the conventional apparatus, an excess amount of the coating liquid applied to the barrel surface of the bottle 151 is wiped away from the barrel surface of the bottle 151 by means of a wiper belt (not shown) to make the barrel surface smooth and frictional. However, since the wiper belt is made of cotton fabrics, the coating liquid can not be sufficiently wiped away from the barrel surface of the bottle 151 to make the barrel surface frictionless whereby a dropping accident of the bottle 151 occurs frequently when the user takes up the bottle 151 by holding the barrel surface thereof with his hand in case that he pours the bottled drink from the bottle 151 after the bottle 151 is delivered as a product. This is another defect inherent in the conventional apparatus. Further, in the conventional apparatus, the bottl 151 is rinsed with water before the coating liquid is applied thereto. However, water vapor tends to condense into water droplets on a lower area of the barrel surface of the bottle 151 to prevent the coating liquid from being sufficiently applied to such lower area of the barrel surface of the bottle 151. This is further another defect of the conventional apparatus. Furthermore, in the conventional apparatus, the coating liquid of the single kind is fed to the barrel surface of the bottle. Consequently, although it is possible to make the barrel surface frictional so as to reduce the slippage accident of the bottle due to characteristics of the coating liquid, provided that the coating liquid is made up of a relatively hydrophilic emulsion (fatty acid ester of sorbitan, monoester of glycerol and the like) containing dimethyl silicone as its main dispersoid element, there exists another defect that the feeling of such coating liquid can not solely provide a sufficient coating for the lower area of the barrel surface of the bottle 151 which has been rinsed with water and dried incompletely to be wet with the condensed water vapor.